Field of the Invention
The present invention relates to repair of a lightning protection material that is provided on a member of an aircraft or the like.
Description of the Related Art
A metal member (referred to as a lightning protection material below) that disperses a lightning current is provided along a surface of an airframe of aircraft that is formed from a carbon fiber reinforced resin (a composite material) in order to impart lightning protection properties.
When the airframe is damaged, it is necessary to perform repair for restoring the airframe including the lightning protection material to an original state.
In the repair, a new lightning protection material is bonded to the airframe in a region where the lightning protection material is lost by a film adhesive (e.g., U.S. Pat. No. 8,246,770).
The film adhesive is formed from a thermosetting resin, and is handled at a low temperature before used. When used, the film adhesive is heated to a predetermined temperature and is thereby cured.
It is convenient to use the film adhesive formed into a uniform thickness for bonding the lightning protection material to the airframe with a stable quality.
Here, the adhesive used for bonding the lightning protection material to the airframe is required to retain a high bonding force over a long period. A curing temperature of the film adhesive that meets the requirement exceeds 100° C. Therefore, when the adhesive is cured, the airframe is also heated to a temperature similar to that of the adhesive.
When the fiber reinforced resin having hygroscopicity is heated to 100° C. or more, moisture accumulated within a structural member (for example, a skin) of the airframe is rapidly evaporated in a large amount, and an internal pressure of the structural member excessively increases. The structural member may be thereby damaged with, for example, a plurality of layers constituting the structural member being separated. In this case, it is necessary to repair the damage secondarily caused by the repair.
An object of the present invention is to repair a lightning protection material provided on a member made of a fiber reinforced resin with a stable bonding quality while avoiding damage caused by moisture existing within the member.